The registration desk is one of the most crowded places in clinical hospitals. One significant character of this clinical setting is that patients may not show up on time or they arrive instantly without appointments, which will cause patients to wait and physicians to remain underutilized. Analyzing the outpatient clinical patient arrival process would be a good start to figure out the bottom line of this problem. In this paper, a process map for block design and open access design will be displayed first. These two design scheduling processes are simulated by the newly developed software Flexsim HealthCare. Patient arrival distribution is obtained through a local community hospital. Factors' effects on the two outputs, patient waiting time and physician utilization have been identified through sequential experiments in order to compare and find out the best schedule. What-if analyses are also performed based on cases under different factors. Suggestions on better schedule rules are made regarding different scenarios.